| CW Squared Ltd | Information & communication | 2018 |
| CWD Group Limited | Financial services | 2025 |
| Cyberscience Corporation Limited | Information & communication | 1987 |
| Cyberscience Limited | Information & communication | 1977 |
| Cybertek Ltd | Information & communication | 1990 |
| Cyclelife Dunstable Limited | Wholesale & retail | 2009 |
| Cygnet Lakeside Doncaster Management Company Limited | Households | 2021 |
| Cypress Bidco Limited | Financial services | 2018 |
| Cypress Debtco Limited | Financial services | 2018 |
| Cypress Midco Limited | Financial services | 2018 |
| Cypress Topco Limited | Financial services | 2018 |
| D Bradford Painting Ltd | Construction | 2014 |
| D E Co Construction Limited | Construction | 2019 |
| D T Flooring Limited | Wholesale & retail | 2011 |
| D Thelma Realty Limited | Real estate | 2025 |
| D&S Packaging Ltd | Manufacturing | 2025 |
| D'Arblay Property Investments (UK) Ltd | Real estate | 2020 |
| D. GEE Limited | Wholesale & retail | 2005 |
| D.E.S.E.A Catering Ltd | Hospitality | 2024 |
| D.F.D. Agency Limited | Wholesale & retail | 2013 |
| D.Gee Enterprises Ltd | Other services | 2011 |
| Daisie Chain Florist Ltd | Wholesale & retail | 2018 |
| Daladale Group Limited | Transport & logistics | 2022 |
| Dale Side Meadows Management Company Limited | Households | 2015 |
| Dalesway (Harrogate) Management Company Limited | Real estate | 2017 |
| Dallington Square Management Limited | Households | 1998 |
| Damien Group Limited | Transport & logistics | 2016 |
| Damp Tech Hertfordshire Ltd | Construction | 2025 |
| DAN Abalasi Ltd | Wholesale & retail | 2025 |
| Danegoods (London) Limited | Wholesale & retail | 1949 |
| Danelsa Limited | Extraterritorial | 2025 |
| Daniel Oliver Services Limited | Construction | 2013 |
| Daniel Selt Consultancy Ltd | Professional & scientific | 2021 |
| Daniel Thomas Estate Agents Ltd | Real estate | 2024 |
| Danii Ltd | Administrative & support | 2018 |
| Danii Properties Limited | Real estate | 2021 |
| Dansoft Maintenance Services Limited | Manufacturing | 2024 |
| Dantech IT Solutions Limited | Information & communication | 2008 |
| DAP Electrical Services Ltd | Construction | 2005 |
| DAP Investments (UK) Ltd | Real estate | 2007 |
| Daps Transport Ltd | Transport & logistics | 2016 |
| Daresbury Garden Village Management Company Limited | Households | 2020 |
| Darkroom Trading Ltd | Hospitality | 2025 |
| Darwin House (Beckenham) Management Company Limited | Households | 2007 |
| Daserv Global Services UK Limited | Other services | 2025 |
| Data Technology Solutions UK Ltd | Construction | 2024 |
| Datacoms Systems Limited | Information & communication | 1997 |
| Date With Pride Ltd | Arts & recreation | 2024 |
| Datum Contracts Hoddesdon Limited | Manufacturing | 2013 |
| Datum Contracts Holdings Limited | Financial services | 2019 |
| Datum Contracts Limited | Manufacturing | 2019 |
| Datum Shopfitting Co. (London) Limited | Manufacturing | 1968 |
| David Bennett Limited | Financial services | 2022 |
| David Page Health & Safety Limited | Professional & scientific | 2013 |
| David Pizey Limited | Administrative & support | 2014 |
| Davmor Limited | Construction | 2008 |
| Davoan Limited | Transport & logistics | 2019 |
| Davroc Limited | Wholesale & retail | 1980 |
| Davyhulme Management Company Limited | Households | 2011 |
| Dawsons Copse Management Company Limited | Households | 1987 |
| DBA Air Solutions Limited | Construction | 2010 |
| DBC (London) Limited | Construction | 2012 |
| DBC Investments Ltd | Real estate | 2018 |
| Dbfb Ltd | Other services | 2024 |
| DC Textiles Limited | Wholesale & retail | 2010 |
| DCS Design and Build Limited | Construction | 2021 |
| DDW Wealth Management Limited | Professional & scientific | 2020 |
| DE Flooring Ltd | Construction | 2017 |
| DE Havilland Grange (Hatfield) Management Company Limited | Households | 2002 |
| DE Vere Homes Limited | Construction | 1986 |
| Deag Electric Ltd | Construction | 2019 |
| Deal Auto Sales Ltd | Wholesale & retail | 2025 |
| Deal Recovery Ltd | Wholesale & retail | 2023 |
| DEE Boutique Ltd | Wholesale & retail | 2023 |
| Deenfs Wills & Probate Ltd | Financial services | 2017 |
| Deer Architects Limited | Professional & scientific | 2026 |
| Defender Construction Ltd | Construction | 2023 |
| DELIVERYSTUFF4YOU Ltd | Transport & logistics | 2021 |
| Delta Property Services Limited | Real estate | 2017 |
| Deluxe Driven Ltd | Administrative & support | 2024 |
| Denise Barrows Consultancy Limited | Professional & scientific | 2016 |
| DER Associates Ltd | Professional & scientific | 2021 |
| Derosa Music Bedford Limited | Wholesale & retail | 2026 |
| Derosa Music Buntingford Limited | Wholesale & retail | 2025 |
| Derosa Music Hertford Limited | Wholesale & retail | 2022 |
| Derosa Music Horsham Limited | Wholesale & retail | 2025 |
| Derosa Music Lichfield Limited | Wholesale & retail | 2025 |
| Derosa Music Saffron Walden Limited | Wholesale & retail | 2023 |
| Design and Create Solutions Ltd | Construction | 2017 |
| Designer Kitchens (East London) Limited | | 1985 |
| Desing World Global Ltd | Wholesale & retail | 2025 |
| Detailing Guides Ltd | Wholesale & retail | 2024 |
| Deuce Tennis Limited | Professional & scientific | 2013 |
| Deverill Estates Limited | Health & social care | 1991 |
| Deverill Holdings Limited | Professional & scientific | 1997 |
| Devonshire Point Residents Management Company Limited | Households | 2014 |
| Dexter Close Management Company Limited | Households | 1997 |
| DGR Investments Limited | Real estate | 2020 |
| DHA Manhattan Nails Ltd | Other services | 2025 |
| Diamond Cutz Ltd | Other services | 2025 |